fix: update innertube clients and fix HLS/DASH quality switching

- Update innertube client versions to match yt-dlp (android 21.02.35,
  ios 21.02.3, web 2.20260114.08.00, android_vr 1.65.10)
- Remove obsolete clients (android-test-suite, ios_vr)
- Replace tv_embedded with TVHTML5_SIMPLY (cn 75)
- Add new clients: web_embedded, mweb, tv
- Fix HLS freeze on quality switch: use nextLevel instead of
  currentLevel, handle bufferStalledError, stream proxy segments
  instead of buffering in memory
- Populate DASH quality selector with actual sources (no Auto)
- Render quality-select empty in template, let JS populate per mode

1 files changed, 72 insertions, 0 deletions

diff --git a/tests/test_watch_formats.py b/tests/test_watch_formats.py
new file mode 100644
index 0000000..85a103b
--- /dev/null
+++ b/tests/test_watch_formats.py
@@ -0,0 +1,72 @@
+import pytest
+from youtube import watch_formats
+
+
+class TestCodecName:
+    def test_avc_returns_h264(self):
+        assert watch_formats.codec_name('avc1.64001F') == 'h264'
+
+    def test_av01_returns_av1(self):
+        assert watch_formats.codec_name('av01.0.05M.08') == 'av1'
+
+    def test_vp9_returns_vp(self):
+        assert watch_formats.codec_name('vp9') == 'vp'
+
+    def test_unknown_returns_unknown(self):
+        assert watch_formats.codec_name('unknown_codec') == 'unknown'
+
+
+class TestVideoQualityString:
+    def test_with_vcodec(self):
+        fmt = {'vcodec': 'avc1', 'width': 1920, 'height': 1080, 'fps': 30}
+        assert watch_formats.video_quality_string(fmt) == '1920x1080 30fps'
+
+    def test_with_vcodec_no_fps(self):
+        fmt = {'vcodec': 'avc1', 'width': 1280, 'height': 720}
+        assert watch_formats.video_quality_string(fmt) == '1280x720'
+
+    def test_with_acodec_only(self):
+        fmt = {'acodec': 'mp4a.40.2'}
+        assert watch_formats.video_quality_string(fmt) == 'audio only'
+
+    def test_empty(self):
+        fmt = {}
+        assert watch_formats.video_quality_string(fmt) == '?'
+
+
+class TestShortVideoQualityString:
+    def test_with_fps(self):
+        fmt = {'quality': 1080, 'fps': 60, 'vcodec': 'av01.0.05M.08'}
+        assert watch_formats.short_video_quality_string(fmt) == '1080p60 AV1'
+
+    def test_h264(self):
+        fmt = {'quality': 720, 'fps': 30, 'vcodec': 'avc1.64001E'}
+        assert watch_formats.short_video_quality_string(fmt) == '720p30 h264'
+
+
+class TestAudioQualityString:
+    def test_with_bitrate(self):
+        fmt = {'acodec': 'mp4a.40.2', 'audio_bitrate': 128}
+        assert watch_formats.audio_quality_string(fmt) == '128k'
+
+    def test_with_sample_rate(self):
+        fmt = {'acodec': 'mp4a.40.2', 'audio_bitrate': 128, 'audio_sample_rate': 44100}
+        assert watch_formats.audio_quality_string(fmt) == '128k 44.1kHz'
+
+    def test_video_only(self):
+        fmt = {'vcodec': 'avc1'}
+        assert watch_formats.audio_quality_string(fmt) == 'video only'
+
+
+class TestFormatBytes:
+    def test_none(self):
+        assert watch_formats.format_bytes(None) == 'N/A'
+
+    def test_bytes(self):
+        assert watch_formats.format_bytes(512) == '512.00B'
+
+    def test_kibibytes(self):
+        assert watch_formats.format_bytes(1024) == '1.00KiB'
+
+    def test_mebibytes(self):
+        assert watch_formats.format_bytes(1048576) == '1.00MiB'
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